The tendency of ceramic tile grout to stain easily requires a high level of maintenance. Overcoming this deficiency has been a high priority for the ceramic tile industry for many years. While heat and chemical resistant grouts, such as epoxy and furan grouts, exist on the commercial market, these grouts contain hazardous ingredients and require the expertise of a professional installer.
The present invention results in a grout product for ceramic tile that is highly resistant to a wide variety of staining agents. The composition takes two forms: a liquid admix for standard portland cement grout and a one component, pre-mixed paste.
Discho U.S. Pat. No. 5,387,644 discloses a hardenable monomer composition useful for grouts. The Disoho composition comprises a mixture of a crosslinkable acrylic monomer, carbon black and/or a polyester- or polyethermethane oltgomer having at least two polymerizable double bonds and a paraffin oil. The oltgomer is an aliphatic or aromatic, bifunctional or polyfunctional polyester- or polyether-urethane acrylate. Therefore, the Discho composition is not a mixture of an acrylic latex, an aliphatic urethane and a paraffin, but the reaction product of a crosslinkable acrylic monomer and a reactive acrylic end-capped polyester- or polyether urethane. Further, the Discho composition is a liquid and the urethane oligomer has a molecular weight of no more than 2,000.